The subject matter disclosed herein relates to transmission gears and, more specifically, to lubrication of transmission gears.
Rotating gears that are utilized to transmit power and/or rotational speed, such as those in a gearbox of a rotary wing aircraft like helicopters, are typically lubricated and/or cooled by a lubricant. The cooling is either by direct spray of the lubricant onto the gears, or by a lubricant bath. In some operating conditions, lubricant is not circulated through the system quickly enough, so that lubricant levels around the gears rise. When lubricant levels rise above a selected level, friction generated between the gear and the lubricant increases. This increased friction caused by the excess amount of lubricant in contact with the gears results in an increased gearbox temperature and decreased power output from the gearbox. The increased friction can further result in a lubricant churning event, in which the result is a rapid, uncontrollable temperature rise and loss of power.